Keyser, Andreas https://orcid.org/0000-0001-5922-5288
Schopka, Simon
Jungbauer, Carsten
Foltan, Maik
Schmid, Christof
Article History
Received: 12 April 2018
Accepted: 26 September 2018
First Online: 3 October 2018
Ethics approval and consent to participate
: The retrospective analysis was approved by the Ethics Committee of the University of Regensburg (reference number 16–104-0189). This institutional review board waived the need for informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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